The Experts below are selected from a list of 321 Experts worldwide ranked by ideXlab platform
E N Bereslavskii - One of the best experts on this subject based on the ideXlab platform.
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on filtration schemes occurring in the problem of flow over a zhukovskii Sheet Pile
Journal of Engineering Physics, 2013Co-Authors: E N BereslavskiiAbstract:Consideration is given to fi ltration under a Zhukovskii Sheet Pile through a ground layer underlain by a highly permeable head horizon the left semiinfi nite part of whose roof is modeled by an impermeable base. A study is made of the case of fl ow where the velocity at the end of the Sheet Pile is equal to infi nity and the fl ow rate takes on extremum values on both water-permeable portions of the boundary of the region of motion. Limiting cases of fl ow associated with the absence of upthrust and of an impermeable inclusion alike are noted, as is an adjacent scheme due to the absence of the two indicated extremum points. Solutions are given for two schemes of motion in a semiinverse formulation, with the classical Zhukovskii problem being the limiting case of one scheme. Distinctive features of such models are noted. For investigation of these fl ows, use is made of a Polubarinova-Kochina method which allows exact analytical representations for motion elements. Results of numerical calculations and the analysis of the infl uence of all physical factors on fi ltration characteristics are given.
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on the problem of flow over a zhukovskii Sheet Pile in an irrigated ground mass
Journal of Engineering Physics, 2012Co-Authors: E N BereslavskiiAbstract:basis of this model, an algorithm of calculation of filtration characteristics is developed for the situations where in water filtration, one has to take account of infiltration onto the free surface. Numerical results and the analysis of the effects of all physical parameters on the flow picture are presented. Consideration is given to the limiting cases of motion associated with the absence of both an impermeable inclusion and the hydrostatic upthrust in the well-permeable underlying layer. The solution is compared with results for the case of a finite flow velocity at the end of the Sheet Pile.
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on flow over a zhukovskii Sheet Pile in an irrigated ground mass
Journal of Engineering Physics, 2011Co-Authors: E N BereslavskiiAbstract:In the hydrodynamic formulation, we solve the problem of plane steady filtration under a Zhukovskii Sheet Pile through an irrigated ground mass underlain by a highly permeable pressure stratum the left semi-infinite part of whose roof is modeled by an impermeable inclusion. Using the P. Ya. Polubarinova-Kochina method, we give a constructive solution of the problem and accurate analytical representations for characteristic dimensions of the flow pattern. Results of the numerical calculations and an analysis of the effects of all physical parameters of the model on filtration characteristics are presented. Consideration is given to limiting cases of flow associated with the absence of an impermeable inclusion as well as of backwater in the underlying well-permeable layer.
Tomohiro Kameoka - One of the best experts on this subject based on the ideXlab platform.
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finite element analysis of earthquake induced damage to anchored Sheet Pile quay walls
Soils and Foundations, 1993Co-Authors: Tomohiro KameokaAbstract:In order to examine the capability of the effective stress model proposed by the authors, a finite element analysis was conducted on the field performance of two quay walls during an earthquake. The quay walls are of anchored steel Sheet Piles. Though the cross sections were similar to each other and the locations were adjacent to each other, one quay wall suffered serious damage while the other did not. The effective stress model used in the analysis consists of a multiple shear mechanism defined in strain space. The model has the capability to represent essential features in the cyclic behavior of sand such as the effects of rotation of principal stress axis directions. For estimating the model parameters, soils were taken from the site for laboratory tests. The record of the earthquake motion was recovered from the site and digitized for the analysis. Results of the finite element analysis are basically consistent with the observed performance of the quay walls; the model demonstrates the potential ability to differentiate between serious large deformations (i.e. damage) from negligibly small deformations (i.e. no damage) in similar types of Sheet Pile quay walls.
Hiroshi Nakazawa - One of the best experts on this subject based on the ideXlab platform.
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behaviour of Pile group behind a Sheet Pile quay wall subjected to liquefaction induced large ground deformation observed in shaking test in e defense project
Soils and Foundations, 2009Co-Authors: Ramin Motamed, Ikuo Towhata, Tsuyoshi Honda, Susumu Yasuda, Kentaro Tabata, Hiroshi NakazawaAbstract:This paper aims to illustrate a large-scale test on a Pile group and a Sheet Pile quay wall which were subjected to liquefaction-induced large ground deformation. The Sheet Pile quay wall was displaced laterally and the 2×3 Pile group was forced by the flow of liquefied soil. This experiment was conducted in March 2006 at the National Research Institute for Earth Science and Disaster Prevention (NIED), Hyogo Earthquake Engineering Research Center, Japan. Liquefaction-induced lateral spreading was achieved, and soil moved laterally about 1.1 m behind the Sheet Pile quay wall. Lateral soil displacement was measured by the inclinometers, and results were in close agreement with the directly observed values. Soil lateral displacement and velocity of soil flow decreased as the distance from the quay wall increased toward the landside. Bending strain records were able to explain the damages to the Piles, yielding at the top and buckling at the middle height. Lateral force of the liquefied soil exerted on the Piles was obtained using earth pressure (EP) sensors and it is shown that rear row Piles (close to the quay wall) received larger lateral forces than front row Piles (far from the quay wall). This behaviour is explained by the distribution of displacement and velocity of the liquefied soil throughout the shaking. In addition, the lateral soil force was back calculated from strain gauge data and the results are compared with the ones directly measured by the EP sensors. Then, the limitations and advantages of the back-calculation approach are elaborated in this study. Moreover, the time history of lateral soil force showed no correlation with either soil or Pile displacements, while it demonstrated a fairly close correlation with the relative velocity until a specific time. This interesting finding would confirm the rate-dependent behaviour of the liquefied soil, though more data from large scale experiments, field testing and centrifuge model tests are needed in this regard.
M. El Sawwaf - One of the best experts on this subject based on the ideXlab platform.
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Experimental and Numerical Study of Strip Footing Supported on Stabilized Sand Slope
Geotechnical and Geological Engineering, 2010Co-Authors: M. El SawwafAbstract:The paper presents the results of laboratory model tests and theoretical analysis on the behavior of a strip footing supported on Sheet Pile wall-stabilized sandy slope and loaded vertically to failure. The parameters varied in the study include the height, stiffness and location of the Sheet Pile wall, the location of the footing relative to the slope crest and the relative density of sand. Two-dimensional plane strain finite element analyses was used to analyze a prototype strip footing on sandy slope with same conditions. The results indicate that the inclusion of Sheet Pile wall has significant effect in improving the response of the strip footing and the slope itself. The theoretical results confirm the experimental results of the model footing tests and show reasonable agreement. Based on the numerical and experimental results, critical values of the Sheet Pile wall parameters for maximum stabilizing effect are established.
Ikuo Towhata - One of the best experts on this subject based on the ideXlab platform.
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mitigation of seismic settlement of light surface structures by installation of Sheet Pile walls around the foundation
Soil Dynamics and Earthquake Engineering, 2015Co-Authors: Rouzbeh Rasouli, Ikuo Towhata, Toshihiko HayashidaAbstract:Abstract Settlement of surface structures, which is particularly a private house, due to subsoil liquefaction is not a new issue in geotechnical engineering. It has been happening during earthquakes in liquefaction-prone areas since many years ago. However, to date no reliable measure against this problem with reasonable cost has been proposed to people. In this paper, results of a series of 1-g shaking table tests which have been conducted to evaluate performance of a possible mitigation against this problem are presented. The proposed mitigation herein is installation of Sheet-Pile walls around the foundation. In order to reduce the cost of mitigation, Sheet-piling with gap and half-length Sheet-piling were examined. The experiments were conducted in different ground water levels. It is found out that installing Sheet-Pile walls in relatively low ground water level can stop settlement of structures completely. Sheet-piling with gaps delays initiation of settlement but it may increase the ultimate settlement of structure. In addition, it is found that formation of a water film under the building׳s foundation is the governing mechanism of post-shaking settlement of structures.
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experimental evaluation of dynamic deformation characteristics of Sheet Pile retaining walls with fiber reinforced backfill
Soil Dynamics and Earthquake Engineering, 2010Co-Authors: R Jamshidi, Ikuo Towhata, Hossein Ghiassian, A R TabarsaAbstract:Fiber reinforced soil behaves as a composite material in which fibers of relatively high tensile strength are embedded in a matrix of soil. Shear stresses in the soil mobilize tensile resistance in the fibers, which in turn imparts greater strength to the soil. In this paper a study on the influence of synthetic fibrous materials in improving the dynamic response characteristics of fine sandy soil is reported. The project aims at converting fibrous carpet waste into a value-added product for soil reinforcement. A series of five shaking table tests using rigid box were carried out on Toyoura sand specimens reinforced with randomly distributed geotextile strips. The dynamic deformation characteristics of the reinforced sand are defined in terms of wall lateral deformation and rotation. The results clearly indicate the effectiveness of fiber reinforcement in improving dynamic properties of fine sand and deformation characteristics of fiber reinforced Sheet Pile retaining wall during shaking.
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behaviour of Pile group behind a Sheet Pile quay wall subjected to liquefaction induced large ground deformation observed in shaking test in e defense project
Soils and Foundations, 2009Co-Authors: Ramin Motamed, Ikuo Towhata, Tsuyoshi Honda, Susumu Yasuda, Kentaro Tabata, Hiroshi NakazawaAbstract:This paper aims to illustrate a large-scale test on a Pile group and a Sheet Pile quay wall which were subjected to liquefaction-induced large ground deformation. The Sheet Pile quay wall was displaced laterally and the 2×3 Pile group was forced by the flow of liquefied soil. This experiment was conducted in March 2006 at the National Research Institute for Earth Science and Disaster Prevention (NIED), Hyogo Earthquake Engineering Research Center, Japan. Liquefaction-induced lateral spreading was achieved, and soil moved laterally about 1.1 m behind the Sheet Pile quay wall. Lateral soil displacement was measured by the inclinometers, and results were in close agreement with the directly observed values. Soil lateral displacement and velocity of soil flow decreased as the distance from the quay wall increased toward the landside. Bending strain records were able to explain the damages to the Piles, yielding at the top and buckling at the middle height. Lateral force of the liquefied soil exerted on the Piles was obtained using earth pressure (EP) sensors and it is shown that rear row Piles (close to the quay wall) received larger lateral forces than front row Piles (far from the quay wall). This behaviour is explained by the distribution of displacement and velocity of the liquefied soil throughout the shaking. In addition, the lateral soil force was back calculated from strain gauge data and the results are compared with the ones directly measured by the EP sensors. Then, the limitations and advantages of the back-calculation approach are elaborated in this study. Moreover, the time history of lateral soil force showed no correlation with either soil or Pile displacements, while it demonstrated a fairly close correlation with the relative velocity until a specific time. This interesting finding would confirm the rate-dependent behaviour of the liquefied soil, though more data from large scale experiments, field testing and centrifuge model tests are needed in this regard.
